Altered neuronal lactate dehydrogenase A expression affects cognition in a sex- and age-dependent manner.

The astrocyte-neuron lactate shuttle (ANLS) model posits that astrocyte-generated lactate is transported to neurons to fuel memory processes. However, neurons express high levels of lactate dehydrogenase A (LDHA), the rate-limiting enzyme of lactate production, suggesting a cognitive role for neuronally generated lactate. It was hypothesized that lactate metabolism in neurons is critical for learning and memory. Here transgenic mice were generated to conditionally induce or knockout (KO) the Ldha gene in CNS neurons of adult mice. High pattern separation memory was enhanced by neuronal Ldha induction in young females, and by neuronal Ldha KO in aged females. In older mice, Ldha induction caused cognitive deficits whereas Ldha KO caused cognitive improvements. Genotype-associated cognitive changes were often only observed in one sex or oppositely in males and females. Thus, neuronal-generated lactate has sex-specific cognitive effects, is largely indispensable at young age, and may be detrimental to learning and memory with aging.

Thermal and solutal heat transport investigations of second order fluid with the application of Cattaneo-Christov theory.

The present examination of mass and heat communication looks at the impact of induced magnetic field, variable thermal conductivity, and activation energy on the flow of second-order liquid across a stretched surface. The mass-heat transfer is also treated using the Model for generalized Fourier and Fick's Laws. The model equations are transformed as needed to produce a system of nonlinear ODEs, which are then numerically solved with the help of BVP4C integrated MATLAB approach. The heat-mass flow parameters are analyzed by the table and graphs. An increment in the estimations of 2nd grade fluid parameter (ß) with magnetic field parameter (M) increase the speed sketch. For the stronger estimations of Schmidt number (Sc), parameter of magnetic field (M) and Eckert number (Ec) have the growing behavior on the temperature profile.

Environmental assessment of toxic heavy metals in bottom sediments of the Sharm Obhur, Jeddah, Saudi Arabia.

The concentrations, spatial distributions, pollution level, and health risks of heavy metals in sediments of the Sharm Obhur, Northern Jeddah, Saudi Arabia were evaluated. Average concentrations were found to be: Cr > Zn > Ni > Cu > As>Pb with the highest concentrations found near the head of the sharm, and decreasing towards the mouth. Environmental indices, together with the statistical analyses, showed that the sharm experiences a low to moderate degree of pollution. Sampling sites with heavy metal contamination are concentrated near the head and the southern coast of the sharm, where intensive human activities associated with a boat dock, construction, and recreation are common. The mean carcinogenic risk (CR) values of As, Cr and Ni are at permissible level suggesting unlikely adverse impacts of heavy metals on human health. Despite acceptable CR values; however, serious non-carcinogenic and carcinogenic health threats from metals may yet be an issue particularly for sensitive populations such as children.

Utilizing combusted PET plastic waste and biogenic oils as efficient pour point depressants for crude oil.

The deposition of paraffin on pipelines during crude oil transit and low-temperature restart processes poses a significant challenge for the oil industry. Addressing this issue necessitates the exploration of innovative materials and methods. Pour point depressants (PPDs) emerge as crucial processing aids to modify paraffin crystallization and enhance crude oil flow. This study focuses on the combustion of polyethylene terephthalate (PET) waste, a prevalent plastic, in two distinct oils (castor and jatropha). The resulting black waxy substances (PET/Castor and PET/Jatropha) were introduced in varying weights (1000, 2000, and 3000 ppm) to crude oil. The PET/castor oil combination demonstrated a remarkable reduction in pour point from 18 to -21 °C at 3000 ppm concentration, significantly more effective than PET/jatropha blends. Substantial decreases in viscosity (up to 75%) and shear stress (up to 72%) were also observed for both blends, most prominently at lower temperatures near the pour point. The synergistic effect of PET and oils as nucleating agents that alter crystallization patterns and restrict crystal growth contributes to this enhanced low-temperature flow. This highlights the potential of PET plastic waste as an economical, abundant, and eco-friendly additive to develop high-performance PPDs for crude oil.

Numerical investigation of the impact of temperature-dependent thermal conductivity and viscosity on thermo-particle heat transfer through stationary sphere and using plume.

Nanofluids have a wide range of applications due to their unique properties, such as enhanced thermal conductivity, convective heat transfer, and mass transfer. These applications can be seen in heat exchangers, cooling systems, and electronic devices to improve thermal performance. To enhance the cooling efficiency and lifespan of electronic devices such as smartphones, televisions, and computers nanofluids are used. These novel types of fluids can be used in energy storage systems, cancer treatment, imaging, and drug deliveryKeeping in mind, the real-time applications in engineering, industry, and science, the current study is carried out. In the present study for heat and mass transportation, the two-phase Buongiorno model for nanofluid is employed to scrutinize Brownian motion and thermophoresis aspects using stationary sphere and plume region. The temperature-dependent viscosity and thermal conductivity effects are encountered in momentum and energy equations, respectively are encountered. The proposed mechanism in the partial differential equations having dimensional form is converted to a non-dimensional form using appropriate dimensionless variables. The solution of the current non-linear and coupled model is obtained using the finite difference method. The numerical solutions presented in graphs and tables indicate that along with heat and mass transfer phenomena are entirely dependent on thermophoresis, Brownian motion, temperature-dependent viscosity, and thermal conductivity. The results indicate that the quantitative behavior of the velocity field is enhanced by increasing values of thermal conductivity variation parameters for both the sphere and the plume region at each position. On the other hand, the reverse trend is noted against the rising magnitudes of the viscosity variation parameter, thermophoresis parameter, and Brownian diffusion parameter. Additionally, the temperature in the plume region declines to enhance thermal conductivity variation parameter. A test for grid independence was performed by considering various grid points. Excellent solution accuracy has been seen as the number of grid points has risen. This ensures the validity and accuracy of the currently employed method. The current results are compared with already published solutions for the validation of the current model for specific cases. It has been noted that there is excellent agreement between both of the results. This close agreement between the results indicates the validation of the current solutions.

Sources and pathways of carbon and nitrogen of macrophytes and sediments using stable isotopes in Al-Kharrar Lagoon, eastern Red Sea coast, Saudi Arabia.

Elemental ratios (δ13C, δ15N and C/N) and carbon and nitrogen concentrations in macrophytes, sediments and sponges of the hypersaline Al-Kharrar Lagoon (KL), central eastern Red Sea coast, were measured to distinguish their sources, pathways and see how they have been influenced by biogeochemical processes and terrestrial inputs. The mangroves and halophytes showed the most depleted δ13C values of -27.07±0.2 ‰ and -28.34±0.4 ‰, respectively, indicating their preferential 12C uptake, similar to C3-photosynthetic plants, except for the halophytes Atriplex sp. and Suaeda vermiculata which showed δ13C of -14.31±0.6 ‰, similar to C4-plants. Macroalgae were divided into A and B groups based on their δ13C values. The δ13C of macroalgae A averaged -15.41±0.4 ‰, whereas macroalgae B and seagrasses showed values of -7.41±0.8 ‰ and -7.98 ‰, suggesting uptake of HCO3- as a source for CO2 during photosynthesis. The δ13C of sponges was -10.7±0.3 ‰, suggesting that macroalgae and seagrasses are their main favoured diets. Substrates of all these taxa showed δ13C of -15.52±0.8 ‰, suggesting the KL is at present a macroalgae-dominated lagoon. The δ15N in taxa/sediments averaged 1.68 ‰, suggesting that atmospheric N2-fixation is the main source of nitrogen in/around the lagoon. The heaviest δ15N (10.58 ‰) in halophytes growing in algal mats and sabkha is possibly due to denitrification and ammonia evaporation. The macrophytes in the KL showed high C %, N %, and C/N ratios, but this is not indicated in their substrates due possibly to a rapid turnover of dense, hypersaline waters carrying most of the detached organic materials out into the Red Sea. The δ13C allowed separation of subaerial from aquatic macrophytes, a proxy that could be used when interpreting paleo-sea level or paleoclimatic changes from the coastal marine sediments.

The efficacy of the ultrasound-guided retrolaminar block versus the classic paravertebral block in patients undergoing unilateral inguinal hernioplasty: a randomized controlled study.

BACKGROUND: In daily surgical practice, inguinal hernioplasty is a frequent procedure that is frequently accompanied by severe postoperative pain. Multiple regional blocks have been described for analgesia after such operations. Retrolaminar block (RLB) is a paravertebral block (PVB) variant that provides excellent analgesia and reduces the risk of complications. This prospective trial compared the analgesic efficacy of PVB and RLB in the inguinal hernioplasty. METHODS: The 56 patients included were randomly assigned into two equal groups according to the block performed under ultrasound guidance at the T12 level: PVB group (28 patients) and RLB (28 patients). Time until the first rescue analgesia was our primary outcome. Other outcomes included the time to perform the block, changes in intraoperative hemodynamic parameters, postoperative VAS, 24-h morphine consumption, the level of patient satisfaction, and the incidence of block-related complications. RESULTS: Demographic data were comparable in the two groups. However, the time needed for the block was significantly shortened with the RLB (p < 0.001). Patients in the PVB groups expressed better pain scores and lower opioid consumption. Additionally, the time to the first call for opioid analgesia showed a significant prolongation in association with the PVB. There was no discernible difference in the frequency of adverse events and recorded MAP and HR. CONCLUSION: The PVB has a superior perioperative analgesic profile compared to the RLB, which manifested in the prolonged duration to the first rescue analgesics, better pain scores, and less opioid consumption, with no significant increase in block-related complications.

Impact of great saphenous vein ablation on healing and recurrence of venous leg ulcers in patients with post-thrombotic syndrome: A retrospective comparative study.

BACKGROUND: The optimal treatment approach for patients with active venous leg ulcers (VLUs) and post-thrombotic syndrome (PTS) associated with great saphenous vein (GSV) reflux remains unclear. To address this gap, we retrospectively compared the outcomes of patients with post-thrombotic VLU with an intact GSV vs those with a stripped or ablated GSV. METHODS: We retrospectively analyzed data from 48 patients with active VLUs and documented PTS, who were treated at a single center between January 2018 and December 2022. Clinical information, including ulcer photographs, was recorded in a prospectively maintained digital database at the initial and follow-up visits. Two patient groups-group A (with an intact GSV) and group B (with a stripped or ablated GSV)-were compared in terms of time to complete healing, proportion of ulcers achieving complete healing, and ulcer recurrence during the follow-up period. RESULTS: There were no significant differences in age, gender, initial ulcer size, or ulcer duration between the two groups. All included patients had femoropopliteal post-thrombotic changes. Group A had significantly more completely healed ulcers (33 of 34 ulcers, 97%) compared with group B (10 of 14 ulcers, 71%) (P = .008). Group A also exhibited a significantly shorter time to complete ulcer healing (median: 42.5 days, interquartile range [IQR]: 65) compared with group B (median: 161 days, IQR: 530.5) (P = .0177), with a greater probability of ulcer healing (P = .0084). Long-term follow-up data were available for 45 of 48 patients (93.7%), with a mean duration of 39.6 months (range: 5.7-67.4 months). The proportion of ulcers that failed to heal or recurred during the follow-up period was significantly lower in group A (9 of 32 ulcers, 27%) compared with group B (11 of 13 ulcers, 85%) (P = .0009). In addition, in a subgroup analysis, patients with an intact but refluxing GSV (12 of 34) had a significantly shorter time to heal (median: 34 days, IQR: 57.25) (P = .0242), with a greater probability of ulcer healing (P = .0091) and significantly fewer recurrences (2 of 12, 16%) (P = .006) compared with group B. CONCLUSIONS: Our findings suggest that removal of the GSV through stripping or ablation in patients with post-thrombotic deep venous systems affecting the femoropopliteal segment may result in delayed ulcer healing and increased ulcer recurrence. Patients with an intact GSV had better outcomes, even when the refluxing GSV was left untreated. These findings emphasize the potential impact of GSV treatment on the management of VLUs in individuals with PTS. Further investigation is needed to validate these results and explore alternative therapeutic strategies to optimize outcomes for this patient population.

Fabrication and Applications of Potentiometric Membrane Sensors Based on Specific Recognition Sites for the Measurement of the Quinolone Antibacterial Drug Gemifloxacin.

Supramolecular gemifloxacin (GF) sensors have been developed. Supramolecular chemistry is primarily concerned with noncovalent intermolecular and intramolecular interactions, which are far weaker than covalent connections, but they can be exploited to develop sensors with remarkable affinity for a target analyte. In order to determine the dose form of the quinolone antibacterial drug gemifloxacin, the current study's goal is to adapt three polyvinylchloride (PVC) membrane sensors into an electrochemical technique. Three new potentiometric membrane sensors with cylindric form and responsive to gemifloxacin (GF) were developed. The sensors' setup is based on the usage of o-nitrophenyl octyl ether (o-NPOE) as a plasticizer in a PVC matrix, ß-cyclodextrin (ß-CD) (sensor 1), γ-cyclodextrin (γ-CD) (sensor 2), and 4-tert-butylcalix[8]arene (calixarene) (sensor 3) as an ionophore, potassium tetrakis (4-chlorophenyl) borate (KTpClPB) as an ion additive for determination of GF. The developed method was verified according to IUPAC guidelines. The sensors under examination have good selectivity for GF, according to their selectivity coefficients. The constructed sensors demonstrated a significant response towards to GF over a concentration range of 2.4 × 10-6, 2.7 × 10-6, and 2.42 × 10-6 mol L-1 for sensors 1, 2, and 3, respectively. The sensors showed near-Nernstian cationic response for GF at 55 mV, 56 mV, and 60 mV per decade for sensors 1, 2, and 3, respectively. Good recovery and relative standard deviations during the day and between days are displayed by the sensors. They demonstrated good stability, quick response times, long lives, rapid recovery, and precision while also exhibiting good selectivity for GF in various matrices. To determine GF in bulk and dose form, the developed sensors have been successfully deployed. The sensors were also employed as end-point indicators for titrating GF with sodium tetraphenyl borate.

Fabrication and Applications of Potentiometric Membrane Sensors Based on γ-Cyclodextrin and Calixarene as Ionophores for the Determination of a Histamine H1-Receptor Antagonist: Fexofenadine.

Supramolecular fexofenadine sensors have been constructed. Although noncovalent intermolecular and intramolecular interactions, which are far weaker than covalent contacts, are the main focus of supramolecular chemistry, they can be used to create sensors with an exceptional affinity for a target analyte. The objective of the current research study is to adapt two PVC membrane sensors into an electrochemical approach for the dosage form determination of histamine H1-receptor antagonists: fexofenadine. The general performance characteristics of two new modified potentiometric membrane sensors responsive to fexofenadine hydrochloride were established. The technique was based on the employment of γ-cyclodextrin (CD) (sensor 1), 4-tert-butylcalix[8]arene (calixarene) (sensor 2) as an ionophore, potassium tetrakis (4-chlorophenyl) borate (KTpClPB) as an ion additive, and (o-NPOE) as a plasticizer for sensors 1 and 2. The sensors showed fast responses over a wide fexofenadine concentration range (1 × 10-2 to 4.5 (4.7) × 10-6 M), with detection limits of 1.3 × 10-6 M and 1.4 × 10-6 M for sensors 1 and 2, respectively, in the pH range of 2-8. The tested sensors exhibit the fexofenadine near-Nernstian cationic response at 56 and 58 mV/decade for sensors 1 and 2, respectively. The sensors exhibit good stability, fast response times, accuracy, precision, and longer life for fexofenadine. Throughout the day and between days, the sensors exhibit good recovery and low relative standard deviations. Fexofenadine in its pure, dose form has been identified with success using the modified sensors. The sensors were employed as end-point indications for the titration of fexofenadine with NaTPB.

Synthesis, DFT calculations, and anti-proliferative evaluation of pyrimidine and selenadiazolopyrimidine derivatives as dual Topoisomerase II and HSP90 inhibitors.

Novel series of aminopyrimidines bearing a biologically active cyclohexenone 3a-f and oxo-selaneylidene moiety 4, besides selenadiazolopyrimidines (5a-e and 7), were synthesised using 5,6-diaminouracils as starting materials. Compound 3a exhibited strong anti-proliferative activity against three cell lines: HepG-2 (IC50 14.31 ± 0.83 µM), A-549 (IC50 30.74 ± 0.76 µM), and MCF-7 (IC50 27.14 ± 1.91 µM). Also, it was four times more selectively cytotoxic against WI-38 cell lines than doxorubicin. Furthermore, Topoisomerase II (IC50 4.48 ± 0.65 µM) and HSP90 (IC50 1.78 ± 0.11 µM) were both strongly inhibited in vitro by 3a. The cell cycle was halted at the G1-S phase, and total apoptotic cells were 65 times more than control Hep-G2 cells. Besides, it increased caspase-3 gene expression, triggering mitochondrial cell death. Molecular docking study indicated that it could bind to Topoisomerase II and HSP90 binding sites in an inhibitory mode. Its geometric properties were investigated using the density functional theory (DFT). Furthermore, compound 3a demonstrated in silico good oral bioavailability.

Predictive modeling of the COVID-19 data using a new version of the flexible Weibull model and machine learning techniques

Statistical modeling and forecasting of time-to-events data are crucial in every applied sector. For the modeling and forecasting of such data sets, several statistical methods have been introduced and implemented. This paper has two aims, i.e., (i) statistical modeling and (ii) forecasting. For modeling time-to-events data, we introduce a new statistical model by combining the flexible Weibull model with the Z-family approach. The new model is called the Z flexible Weibull extension (Z-FWE) model, where the characterizations of the Z-FWE model are obtained. The maximum likelihood estimators of the Z-FWE distribution are obtained. The evaluation of the estimators of the Z-FWE model is assessed in a simulation study. The Z-FWE distribution is applied to analyze the mortality rate of COVID-19 patients. Finally, for forecasting the COVID-19 data set, we use machine learning (ML) techniques i.e., artificial neural network (ANN) and group method of data handling (GMDH) with the autoregressive integrated moving average model (ARIMA). Based on our findings, it is observed that ML techniques are more robust in terms of forecasting than the ARIMA model.

Modeling and Forecasting Monkeypox Cases Using Stochastic Models.

BACKGROUND: Monkeypox virus is gaining attention due to its severity and spread among people. This study sheds light on the modeling and forecasting of new monkeypox cases. Knowledge about the future situation of the virus using a more accurate time series and stochastic models is required for future actions and plans to cope with the challenge. METHODS: We conduct a side-by-side comparison of the machine learning approach with the traditional time series model. The multilayer perceptron model (MLP), a machine learning technique, and the Box-Jenkins methodology, also known as the ARIMA model, are used for classical modeling. Both methods are applied to the Monkeypox cumulative data set and compared using different model selection criteria such as root mean square error, mean square error, mean absolute error, and mean absolute percentage error. RESULTS: With a root mean square error of 150.78, the monkeypox series follows the ARIMA (7,1,7) model among the other potential models. Comparatively, we use the multilayer perceptron (MLP) model, which employs the sigmoid activation function and has a different number of hidden neurons in a single hidden layer. The root mean square error of the MLP model, which uses a single input and ten hidden neurons, is 54.40, significantly lower than that of the ARIMA model. The actual confirmed cases versus estimated or fitted plots also demonstrate that the multilayer perceptron model has a better fit for the monkeypox data than the ARIMA model. CONCLUSIONS AND RECOMMENDATION: When it comes to predicting monkeypox, the machine learning method outperforms the traditional time series. A better match can be achieved in future studies by applying the extreme learning machine model (ELM), support vector machine (SVM), and some other methods with various activation functions. It is thus concluded that the selected data provide a real picture of the virus. If the situations remain the same, governments and other stockholders should ensure the follow-up of Standard Operating Procedures (SOPs) among the masses, as the trends will continue rising in the upcoming 10 days. However, governments should take some serious interventions to cope with the virus. LIMITATION: In the ARIMA models selected for forecasting, we did not incorporate the effect of covariates such as the effect of net migration of monkeypox virus patients, government interventions, etc.

Isotope signature and elemental characteristics of subsurface formations around deep-laying coal seams probed by means of atomic and nuclear-based techniques.

A systematic investigation on the isotopic and elemental signature, for both stable and radioactive elements, and mineral contents was performed to examine the characteristics of subsurface formations collected at different depths between 3.962 km and 4.115 km around deep-laying coal seams located under the Marmarica plateau in Egypt. Concentrations of major and minor oxides (Na2O, MgO, Al2O3, SiO2, SO3, K2O, CaO, TiO2, MnO, ΣFeO + Fe2O3, SrO, ZrO2, and BaO) were determined by X-ray fluorescence and dependencies among these concentrations revealed the type and sort of the formations. Organic contents were determined by Fourier Transform infrared spectroscopy to investigate the variation of the CO/CC bonding ratio with depth. Rare earth elements (REE), specifically Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu were determined by inductively coupled plasma mass spectrometry while actinoids were detected by the radioactive decay of its daughter nuclei. The results showed a high trapping of REE elements and actinoids in layers above the coal seams which indicates the occurrence of aqueous flow followed by possible sorption in these layers. The mobility of the fluid was investigated using the process radioactive decay series between Ra226 and Ac228 from one side and their daughters from the other side.

Heavy metals concentrations and speciation of Pb and Ni in airborne particulate matter over two residential sites in Greater Cairo - reflection from synchrotron radiation.

Synchrotron radiation-based techniques [X-ray absorption near-edge structure (XANES) and X-ray fluorescence (XRF)] combined with inductively coupled plasma-mass spectrometry (ICP-MS) were used for the assessment of heavy metals concentrations as well as lead (Pb) and nickel (Ni) speciation in airborne particulate matter (PM10) over two residential sites in Greater Cairo. Nineteen 24 h high-volume samples collected at Giza (G) Square and Helwan (H) University (Egypt) were selected for this study. Mean concentrations of heavy metals in PM10 at both sites were found to have the same descending order of Pb > Cu > Ni > Cd > Co > As, of which concentrations of Pb, Cu, Ni and Cd in H samples were higher than those in G samples. For Pb, synchrotron-based XRF results were in good agreement with concentrations obtained by ICP-MS. The XANES spectra of PM10 at the Pb L2-edge and Ni K-edge were compared with those of Pb and Ni in model standard compounds to provide information on the potential oxidation states as well as the chemical forms of those elements. The data show that Pb has similar chemical environments in both series G and H with the predominance of Pb2+ oxidation state. Nickel was found as Ni(OH)2, NiO and Ni metal in the analyzed samples. However, the content of Ni in the background filter shows a very strong interference with that of the collected PM10. Carcinogenic and non-carcinogenic risks resulting from the inhalation of the studied heavy metals were assessed for children and adult residents and were found below the safe limits, at both sites.

The Truncated Burr X-G Family of Distributions: Properties and Applications to Actuarial and Financial Data.

In this article, the "truncated-composed" scheme was applied to the Burr X distribution to motivate a new family of univariate continuous-type distributions, called the truncated Burr X generated family. It is mathematically simple and provides more modeling freedom for any parental distribution. Additional functionality is conferred on the probability density and hazard rate functions, improving their peak, asymmetry, tail, and flatness levels. These characteristics are represented analytically and graphically with three special distributions of the family derived from the exponential, Rayleigh, and Lindley distributions. Subsequently, we conducted asymptotic, first-order stochastic dominance, series expansion, Tsallis entropy, and moment studies. Useful risk measures were also investigated. The remainder of the study was devoted to the statistical use of the associated models. In particular, we developed an adapted maximum likelihood methodology aiming to efficiently estimate the model parameters. The special distribution extending the exponential distribution was applied as a statistical model to fit two sets of actuarial and financial data. It performed better than a wide variety of selected competing non-nested models. Numerical applications for risk measures are also given.

Neutron-induced mass shift of tin isotopes recognized using inductively coupled plasma mass spectrometry as an isotopic fingerprint on neutron reactions.

The phenomenon of isotope shift in response to neutron irradiation was investigated. The high fission-neutron fluence of 1.44×1018 cm-2 from the second Egyptian research reactor (ETRR-2) was used to induce a mass shift in a metallic tin sample. A triple-quadrupole inductively coupled plasma mass spectrometry system was used to analyze the isotope abundances in the mass range from A=111 to A=125. The problem of mass bias due to kinetic fractionation on use of the inductively coupled plasma mass spectrometry system was treated by our calibrating the mass bias with a standard reference tin solution and building a response function. The response function was used to obtain absolute abundances in each mass range instead of isotope ratios. The results show that the mass shifts in the irradiated sample are dependent on the cross section of the neutron capture reaction in the tin isotopes.

Nuclear Radiation Shielding Characteristics of Some Natural Rocks by Using EPICS2017 Library.

Radiation leakage is a serious problem in various technological applications. In this paper, radiation shielding characteristics of some natural rocks are elucidated. Mass attenuation coefficients (µ/ρ) of these rocks are obtained at different photon energies with the help of the EPICS2017 library. The obtained µ/ρ values are confirmed via the theoretical XCOM program by determining the correlation factor and relative deviation between both of these methods. Then, effective atomic number (Zeff), absorption length (MFP), and half value layer (HVL) are evaluated by applying the µ/ρ values. The maximum µ/ρ values of the natural rocks were observed at 0.37 MeV. At this energy, the Zeff values of the natural rocks were 16.23, 16.97, 17.28, 10.43, and 16.65 for olivine basalt, jet black granite, limestone, sandstone, and dolerite, respectively. It is noted that the radiation shielding features of the selected natural rocks are higher than that of conventional concrete and comparable with those of commercial glasses. Therefore, the present rocks can be used in various radiation shielding applications, and they have many advantages for being clean and low-cost products. In addition, we found that the EPICS2017 library is useful in determining the radiation shielding parameters for the rocks and may be used for further calculations for other rocks and construction building materials.

Mixed convection flow along a curved surface in the presence of exothermic catalytic chemical reaction.

In the current study, the attention is paid on the phenomena of mixed convection flow under the effect of exothermic catalytic chemical reaction along the curved surface. The proposed problem is modeled in nonlinear coupled partial differential equations. In keeping view the principle of homogeneity the dimensional flow model is transformed into dimensionless by using an appropriate scaling. This well arranged form of equations is then discretized with the aid of finite difference method for the numerical solution. The solutions of the considered model are estimated and displayed in the graphs. Here, in the contemporary study variables of physical significance such as velocity profile, temperature distribution and mass concentration are encountered efficiently. The incorporated pertinent dimensionless numbers that is body shape parameter, mixed convection parameter, modified mixed convection parameter, Prandtle number, exothermic parameter, chemical reaction parameter, temperature relative parameter, dimensionless activation energy parameter, and Schmidt number for which variations in the concentrated physical variables are estimated and presented in graphical way. For each boundary conditions computations are performed along the curved surface for different body shape parameter (n) values range from 0 up to 0.5; the obtained results satisfied by the boundary conditions. The velocity profile becomes increasingly more significant for n equal to 1 and due to the uniformly heated surface temperature profile and mass concentration are uniformly distributed.

Comparison of Single Photon Emission Computed Tomography (SPECT) and implantable Doppler in the monitoring of a vascularised fibular free flap for reconstruction of the mandible.

Monitoring of microvascular free flaps is an influencing factor in the success or failure of the treatment. In this study, we aim to compare the accuracy of implantable Doppler and scintigraphy in the monitoring of a vascularised buried fibular graft for reconstruction of the mandible. In a prospective cohort study, an implantable Doppler was placed intraoperatively, and Single Photon Emission Computed Tomography (SPECT) was taken in patients when abnormal blood flow was detected via the implantable Doppler or 48 hours after operations in patients with normal signals on the Doppler. The flaps were explored if patients did not have regular signals via implantable Doppler or if SPECT revealed impaired perfusion. The number of true- and false-positive cases and true- and false-negative cases were documented. Positive predictive value (PPV) and negative predictive value (NPV) were calculated. Eighteen (29%) of 62 patients underwent explorative surgery. The sensitivity of SPECT was 38.88%, and specificity was 97.72%. In SPECT, PPV was 87.50% and NPV 79.62%. The sensitivity of the implantable Doppler was 72.22%, and specificity was 93.08%. In assessment with the implantable Doppler, PPV was 81.25% and NPV 93.18%. It seems that SPECT and the implantable Doppler had sufficient specificity in the monitoring of a buried fibular graft. However, SPECT had a lower sensitivity than the implantable Doppler.